diff --git a/src/devices/machine/ncr5380n.h b/src/devices/machine/ncr5380n.h
index ae9a87b4344..fbbf9cba616 100644
--- a/src/devices/machine/ncr5380n.h
+++ b/src/devices/machine/ncr5380n.h
@@ -133,7 +133,7 @@ private:
 
 	// state machine
 	emu_timer *m_state_timer;
-	enum state : unsigned
+	enum state : uint32_t
 	{
 		IDLE,